Hydraulic door keeper



5 Sheets-Sheet 1 Original Filed Dec. 4, 1956 Hemz Bomm INVENTOR.

Aug. 28, 1962 H. BOMM HYDRAULIC DOOR KEEPER 5 Sheets-Sheet 2 Original Filed Dec. 4, 1956 Heinz BOMM INVENTOR.

fleslem, Ross 8 flestem 5 Sheets-Sheet 3 Original Filed D60. 4, 1956 FIG.1O

Heinz BOMM INVENTOR.

esfze .Mesim 8 M m Aug. 28, 1962 H. BOMM 3,050,769

HYDRAULIC DOOR KEEPER Original Filed Dec. 4, 1956 5 Sheets-Sheet 4 fiT FIG.I4

Heinz Bomm INVENTOR.

fluid", 8 MGM Aug. 28, 1962 H. BOMM 3,050,769

HYDRAULIC DOOR KEEPER Original Filed Dec. 4, 1956 5 Sheets-Sheet 5 Heinz BOMM INVENTOR.

United States Patent Ofilice 3,50,759 Patented Aug. 28, 1962 3,050,769 HYDRAULIC DOOR KEEPER Heinz Bomm, Ennepetal-Voerde, Germany, assignor to Firmn Dorken & Mankel K.G., Ennepetal-Voerde, Germany Original application Dec. 4, 1956, Ser. No. 626,235, new Patent No. 2,965,917, dated Dec. 27, 1960. Divided and this application Nov. 17, 1958, Ser. No. 781,177 Claims priority, application Germany Aug. 3, 1956 3 Claims. (3. 16-55) The invention relates to a hydraulic door keeper having a pivot and a torsion spring arranged with its axis parallel to the said pivot, as well as linkages connecting the spring to the pivot for a door swing of at least 180.

Hydraulic keepers of a great many different types are known, both for doors opening in one direction and for swinging doors. Swinging-door keepers have a swing of 180, while keepers for doors opening in one direction generally have a swing of only 90. However, keepers having a swing of 180 for doors opening in one direction are also known. Difficulties commonly arise in connection with accommodating the keeper Within a small space without sacrifice of efiiciency of the mechanism. Thus all known door keepers have disadvantages consisting either in large size, requiring a large floor opening, or in unsatisfactory function, or both. For example, door keepers often make use of helical springs acting in tension or compression. In the arrangement of these springs, the maximum restoring force, owing to limitations of attachment, is not effective near the closed position of the door, with the result that the closure pressure is inadequate, while in other positions the spring action is stronger and makes the door hard to open. Furthermore, the restoring force of the springs lies within a swing of 180, so that such keepers are not serviceable for doors opening in one direction which, to avoid dead space behind the door, are to swing 180 without sacrifice of automatic return.

In swinging-door keepers, apart from the said helical tension or compression springs, spiral springs are frequently employed. Since the closed position of swinging doors lies midway in the 180 swing, and the restoring force must therefore act in two different directions, the keepers are constructed with two sp' al springs, which increases their size. Means are known, however, for constructing such swinging-door keepers with a single helical spring, which is wound up or down according to the side on which the door is opened. Such helical springs likewise require ample space and large size of unit. Furthermore, the reversing loads. on the spring soon result in fatigue of the material, leading to relaxation and ultimate failure of the spring.

The present invention, then, is addressed to the problem of improving such door keepers so as to avoid the said disadvantages and achieve satisfactory function with extreme simplicity of construction and small size.

This problem is solved essentially in that the restoring spring used is preferably a spiral spring acting in one di rection, having one end attached to the casing and the other end to a first stud or winder serving to regulate the spring tension and that a connection is established between the spring-urged stud with a second stud acting as a door pivot, by tension members including articulated linkages whose moment arms ar so proportioned with respect to the pivot stud and the spring-loaded stud as to exercise the maximum closing force in the closed position of the door, the pivot stud being advantageously linked to the pistonof a hydraulic damping cylinder to control the closing pressure. By the provision of a single spiral spring for returning a door with 180 swing in a keeper according to the invention, extreme simplicity of construction and small size are attained, permitting a small floor opening for the keeper. The linkages include bars that are pivotally connected with opposite extremities of a connecting rod and with respective cranks on the two studs in such manner as to exert the maximum closing force in the closed positions; this alfords to the keeper, despite the soft spring action of a spiral spring, a strong closing pressure and efiicient operation. At the same time, the spiral spring of a swinging door is loaded in one direction only, thus substantially diminishing fatigue of material and lengthening service life compared to a spring loaded in both directions. The unidirectional loading of the spring and the maximum of closing force in closed position of the door is attained by a suitable dimensioning of the articulated linkages that determine the position of closure, the arrangement being such that one linkage unwinds itself from the first stud and winds itself on the second stud as the door is swung to rotate these studs against the spring force. The connecting rod, or one such rod if two are provided in the case of a swinging door, intersects the common axial plane of the two studs, the second connecting rod (if any) being positioned on one side of that plane. Stops are advantageously disposed alongside these rods to limit the outward excursion of either rod when the other is tensioned by a movement of the door in one or the other direction.

The device according to the invention will now be more fully described with reference to the accompanying drawing, but it should be understood that the same is given merely by way of illustration and not of limitation and that many changes in the details may be made without departing from the spirit of the inveniton.

In the drawing:

FIG. 1 shows an embodiment of a keeper for swinging doors in longitudinal section along the line I-I in FIG. 2;

FIG. 2 shows a top view of the same embodiment with cover plate removed, partially in section on the line IIII of FIG. 1 and omitting, for the sake of clarity, the lines drawn in FIG. 4a to represent the guide roller ofthe damping mechanism;

FIG. 3 shows a transverse section along the line III-III in FIG. 2;

FIG. 4 is a transverse section showing the lever system at the section line IVIV in FIG. 1 with the door closed;

FIG. 4a is a transverse section showing the connections to the damping mechanism at the section line IVa IVa in FIG. 3, in the same position of the door as in FIG. 4;

FIG. 5 is a sectional view taken on the same section line as FIG. 4 showing the lever system with the door opened counterclockwise;

FIG. 6 is a sectional View taken on the same section line as FIG. 4 showing the lever system with the door opened clockwise;

FIG. 7 is a longitudinal section of the cushion chamher as seen from above with the door closed;

FIG. 8 is a longitudinal section of the cushion chamber with the door opened;

FIG. 9 is a diagrammatic representation of the arrangement of tension members with the door closed, in another embodiment;

FIG. 10 shows the same with the door opened counterclockwise;

FlGkll shows the same with door opened clockwise;

FIG. 12 shows another embodiment of a keeper for doors swinging in one direction, in top view, with door open;

FIG. 13- shows the same in side view, in secti0n'X[lI XIII of FIG. 12; p

FIG. 14 shows a portion of the same in section XIV- XIV of FIG. 13;

FIGS. 15-17 show various positions of the push rod, in diagrammatic form.

In FIGS. 1 to 8, a housing 1 accommodates all me- 3 chanical parts including the hydraulic damping system, and is closed off dustproof at the top by cover plates 2 and 3. The pivot stud 4 revolves in a bearing boss 5 in cover 2 and a thrust bearing 6in the bottom of housing 1. In the center of bearing 6, as a foot bearing to carry the Weight of the door, a large ball is accommodated, the upper half of which fits a matching recess in the pivot 4. Cover plate 3 has a bearing boss 7, and the bottom of housing 1 carries another bearing 8, two pins 9, 9 forming an axle for the winder 9 of spring 14 being journaled in these bearings. The bottom pin 9' of the winder bears a crank arm 10. The crank 10 is fixedly attached'to the winder by a screw 11, FIGS. 4, 5, 6. The crank 10 is connected to the pivot 4 by connecting rods 12, 12' and cranks 13, 13'. The connecting rods 12, 12' are articulated to the crank 10 with pins located both on the same side of the line between centers of the pivot 4 and the spring 14. Winder 9 and its pins 9', 9" may be regarded as another stud loaded unidirectionally by spring 14 for rotation about its axis.

At the other end, connecting rods 12, 12 are articu-' through the line between the pivot and spring studs. The

cranks lie one above the other, are rotatably mounted on the pivot 4, and include a catch 15, integral with the pivot, between them. 7

' The restoring spring 14, for example a flat spring, is hooked by its outer flange 14' to housing 1 and by its inner flange 14 to the winder 9, and, when wound, will pull crank 10 and connecting rod 12,12 steadily in the direction of arrow a (FIG. 4) until cranks 13, 13' rest against the catch 15 to right and left. A rigid connection is thus formed from spring 14 to the square 16 on pivot 4, transmitting the closing force of the spring to the door through a lever mounted on the square. In the position described and represented in FIGS. 2 and 4, with the door closed, the initial force of the spring acts to draw cranks '13, 13 hard against the faces of catch 15, thus holding the door in closed position. The articulations of connecting rods 12, 12', both on the spring side and on the pivot side where they jointhe cranks 13, 13', are so chosen that the highest closing pressure is provided in the first 1020 of opening to the right or left. This means conversely' a maximum closing pressure in the last 1020 of the closing motion, 'or precisely in the critical range of closure. This ensures positive closing of the door at the torque on the door will then decrease by A to A, this 7 decrease ending at about 40. From 40 to 110 the torque remains constant.

This is due not only to the length of the cranks 13 and crank 10, but also to the" position of the swing of these relative to the line joining the pivot and the pin of the spring, as well as the variation of the spring force with angle of swing. The moment arm of the connecting rod.

12 with respect to stud 9, 9', 9", on commencement of closure at'110, is very long, becoming less until the minimum lever arm is reached at the end of the closingfopen ation.- At commencement of closure, the spring 14 is much morestrongly Wound than in rest position, trans- I its force via the engaged crank 13 to the catch 15, which tends to turn the pivot4and hence to close the door. The connecting rod 12' with crank 13' meanwhile executes an idle movement on the other side of pivot 4, without transmitting any force or action. If the door is moved clockwise, or in other Words in the direction of the arrow in FIG. 6, the process is the same except that now connecting rod 12 with crank 13' transmits the force and movement, while connectingrod 12 and crank 13 folthe screw 11, FIG. 4, becomes visible.

The screw 11 is screwedgdown until it encounters a recess provided in the bottom of the housing whereby the crank 10 is secured against rotation, but the winder is disengaged and may be rotated relative to the lever 10. The stud 9, 9, '9" is rotated until another hole lies im mediately abovethe screw 11, whereupon the crank and the spring can be'reengaged with each other.

The movement of the keeper mechanism is paralleled by that of the damper mechanism. The first 30 of closing movement, or from 11-0 to 80, are traversed at high speed, followed by a gentle adjustably retarded movement. The high speed is intended to avoid leaving the door open too long in retarded return movement, but is so proportioned as not to interfere with trafiic.

The damper system is actuated from the pivot 4. i cam 17 fixedly connected to the pivot, 4 presses, as the door closes, against a roller 19 mounted in guide mem her 18, moving the latter around pivot 4. Guide member 18 is articulated to lever 20, connected to pin 21. In known manner, pin 21 is provided below with a crank and pin moving the. damper piston 23 back and forth inthe damper cylinder 24, by means of piston rod 22.,

'- When the door is opened, the guide member 18 moves in the direction oiarrow b (FIG. 3)..

The hydraulic fluid contained in the crank chamber flows through an open ball valve, not shown, in'piston 23 into, the cylinder chamber. When the door closes, piston 23 moves in the direction of arrow 0 (FIG. 8) and, under the load of the keeper spring, exerts pressure on the hydraulic fluid, whereby the ball valve is closed and the fluid must make its way through a passage with regulating valve 25 to return to the space behind the damper piston 23.

Depending on the port area, variable by means of valve I 25, the closing speed of the door can be regulated. The' stroke of piston 23 per degree of door angle is nearly constant from 80 m 0, so that there is an equalized damping efiect throughout this range. By means of another valve 26, the final swing (sudden closure overthe last 8-10 of closing movement) can be hydraulically controlled, an important point for striking doors requiring to be pushed into locked position. The final slamlcanbe' shut ofi entirely by means of valve 26, or so adjusted that the final speed will meet specific requirements. The crank 1' 21, in'this arrangement of guide member 18, moves inone direction only regardless of the direction of opening of the door.

This achieves a reliable damping action down to V closure, even in the case of swinging doors. Beneath cam 17, a follower 27, FIG. 4a, .is provided,':resting against the lug 28 of guide member 18 and serving to return guide member 18 when the door is opened.

The housing 1 is so accommodatedin a ing that it can be set in a horizontal plane about: pivot 4 in order to correct inaccuracies of installation,

In FIGS. 9 toll, the pivot 4 is provided with'two cranks 31, 31" fixedly attached thereto. Connecting bars 32a, 32b and 32a", 32b" join the cranks 31', 31 to connecting rods 33' and 33" which are articulated at the otherend by a bar 34 to a commoncrank arm '35 on; winder9. It should be noted that in FIGS..911 pivot V 4 and winder 9 have a construction identical with shaft 4 and winder 9 shownin FIGS. 1'to 3. The end of con-' protective 7 necting rod 33' articulated to bar 34 is forked and embraces the adjacent end of connecting rod 33", while bar 34 consists of a pair of straps embracing the ends of the connecting rods 33' and 33". Rod 33" intersects the common axial plane of pivot stud 4 and Winder 9.

The connecting rods 33 and 33" are articulated to bar 3 4 by means of a common pin 36. Bar 34 folds against crank 35, resting against a surface 37 thereon, while bars 32a, 32b and 32a, 32b" can similarly fold up against the cranks 31, 31 so as to come to rest against surfaces 38, 39 thereof. Connecting rods 33' and 33 are guided by stops 41, 41" which limit their outward excursion.

In FIGS. 12 and 13, a housing 55, let into the floor in known manner within an outside casing, not shown, accommodates the pivot 4 and spring 14. 'In spring 4, a winder 9 is rotatably mounted, with an attached crank arm 57. To crank 57 a bar 58 is attached, articulated to a connecting rod 59. Bar 58 is articulated to a lateral extension of crank 57 for limited angular motion related thereto. The pivot 4 is provided with a crank 61 connected to the other end of connecting rod 59 by a bar 42. The pivot 4 turns in bearings mounted in the bottom of housing 55 and a cover 43 closing 01? a damper chamber 44 partitioned from the interior of housing 55. The bearing in cover 43 is protected by a centered stutfing box 45 centering the cover 43 in a recess '46 of housing 55. Rod 59 intersects the common axial plane of the studs, the same as rod 33" in the preceding embodiment.

Cover 43 is rigid with a damping cylinder 47, accommodating piston 48. Piston 43 is connected to pivot 4 by a crank mechanism Gil. From the cylinder chamber of the damper system, an outlet passage 49 leads in known manner to the damping chamber 44, whose outlet aperture is variable by a screw 5% for regulation of the damping elfect; the necessary return path to the chamber 44, described in connection with FIGS. 1-8, has not been i1- lustrated. Passage 49 contains a relief valve 51 which allows hydraulic fluid to escape into chamber 44 in event of excess pressure in the cylinder chamber.

The mode of operation of the keeper according to IGS. 12-17 is as follows.

With the door closed, member 58 rests against surface 52 of crank 57, while member 42 and connecting rod 59 are extended in line (FIGS. 12 and 15). Then, upon opening of the door, the lever arm of crank 61 acts upon the pivot 4, while the efifective moment arm between rod 59 and the stud 9, 9', 9" (i.e. the distance between rod '59 and the stud axis) is very short. This leverage results in an initial high restoring force at the commencement of opening. Upon enlargement of the angle of opening of the door, member 58 is lifted Ofi crank 57, thus increasing'the effective moment arm of rod 59 relative to the axis of rotation of winder 9. This increased leverage reduces the force transmitted to connecting rod 59. At the second stud represented by pivot 4, member 42 comes to rest against surface 53 of crank 61 in the course of the opening operation. In the final position at 180, connecting rod 59 likewise comes to rest against a surface 54 of crank 61, thereby further reducing its effective moment arm with respect to the axis of stud 4. This reduction of leverage additionally intensifies the force reduction due to the lengthening of the moment arm acting at the spring end. Thus the force required to open the door is steadily diminished. In the closing operation, this atfords the advantage that during the initial travel, not hydraulically controlled, the starting speed is not excessive, While during the control travel the now inverted leverage progressively increases the closure force until the maximum is reached 10" ahead of final closure.

It will be apparent that the changes in the moment arms between rods 33, 33" and the stud axes in FEGS. 911 are analogous to those just described with reference to the embodiment of FIGS. 12-17.

The present application is a division of application Ser. No. 626,235, filed December 4, 1956, now Patent No. 2,965,917.

I claim:

1. A door keeper comp-rising a first and a second stud parallel to each other, spring means tending to rotate said first stud in a predetermined direction about its axis, said second stud being provided with coupling means for connecting it to a swingable door, and transmission means positively interconnecting said studs for joint rotation about their axes; said transmission means comprising a rod intersecting the common axial plane of said studs, a first articulated linkage including a first crank coupled with said first stud and a first connecting bar pivotally connected to said first crank and to one extremity of said rod, and a second articulated linkage including a second crank coupled with said second stud and a second connecting bar pivotally connected to said second crank and to the other extremity of said rod, said linkages being so dimensioned that said first linkage unwinds itself from said first stud While said second linkage Winds itself upon said second stud upon rotation of said second stud with entrainment of said first stud in a direction opposing the force of said spring means.

2. A door keeper comprising a first and a second stud parallel to each other, spring means tending to rotate said first stud in a predetermined direction about its axis, said second stud being provided with coupling means for connecting it to a swingable door, and transmission means positively interconnecting said studs for joint rotation about their axes; said transmission means comprising a first rod intersecting the common axial plane of said studs, a second rod on one side of said plane, a first articulated linkage including a first crank coupled with said first stud and a first connecting bar pivotally connected to said first crank and to one extremity of each of said rods, a second articulated linkage including a second crank coupled with said second stud and a second connecting bar pivotally coupled to the other extremity of said first rod, and a third articulated linkage including a third crank coupled with said second stud and a third connecting bar pivotally connected to said third crank and to the other extremity of said second rod, said linkages being so dimensioned that rotation of said second stud in either direction tensions a respective one of said rods for rotary entrainment of said first stud in a direction opposing the force of said spring means, the tensioned rod having an increasing moment arm with respect to said first stud and a decreasing moment arm with respect to said second stud upon said entrainment.

3. A door keeper according to claim 2, further comprising stop means positioned alongside said rods for limiting the outward excursion of each rod upon a tensioning of the other rod.

References Cited in the file of this patent UNITED STATES PATENTS 799,342 Jordan Sept. 12, 1905 1,064,255 Rixon June 10, 1933 2,669,745 Rydberg Feb. 23, 1954 

